The exemplary embodiment relates to public transportation and finds particular application in connection with a system and method for localization of tags used for making transport transactions.
In conventional public transportation systems, travelers pay for a trip and receive a single or multi-journey ticket which is used to verify that the traveler has paid for the trip. Prepaid tickets can be paper, magnetic or contactless cards. Such solutions often require substantial investments in infrastructure, including ticket readers, ticket dispensers, and recharging stations. Additionally, the use of tickets can cause delays in boarding of a bus at a busy stop, as each traveler takes time to provide exact change for a ticket or scans a pre-purchased ticket for validation.
More recently, systems have been proposed which allow travelers to pay for trips using smart phones which interact with a smart tag located on a transportation vehicle or at one of the stops. The passenger taps the phone on the tag at boarding and alighting locations. To minimize the cost of the tags, information on the transactions is sent by the travelers' phones to a central server where invoicing functions are performed. The tag provides the phone with information that is used to compute the price of the trip. The trip price is often based on the boarding and alighting locations and time. One problem with this approach is that for tags mounted on moving vehicles, the location changes as the vehicle moves along the route. The tag may be provided with a global positioning system (GPS) capable of generating the location information. However, this adds complexity and cost to the tags and also causes the tags to consume more power, which is an issue when the tags are battery powered. One option would be to delegate the generation of the location information to the user's phone, which is typically provided with GPS capability. However, this may raise the possibility of fraud or inaccuracy if the phone is out of GPS coverage or if its GPS capability is turned off. In addition, the delay in obtaining a valid and accurate GPS position is quite variable (it depends on GPS signal strength and time of last position acquired) and thus may not be received within a standard transport validation time of less than about one second. Another option would be to combine the time of the transaction with the operational data of an automatic vehicle location system to determine the boarding and alighting locations a posteriori. However, this would need an extremely reliable and accurate automatic vehicle location system.
Thus, it would advantageous to provide a system and method for providing location information to a transportation vehicle which is low in cost and secure.